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25 series - Iupc interface protocol stack

Up to the 25 series 25.450 - UTRAN Iupc interface general aspects and principles 25.451 - UTRAN Iupc interface layer 1 25.452 - UTRAN Iupc interface: signalling transport 25.453 - UTRAN Iupc interface Positioning Calculation Application Part (PCAP) signalling


The Iupc interface is an optional interface, which is used where positioning functions are carried out in a remote component known as the SAS. The Iupc interface connects an RNC to an SAS.

Like the other UTRAN interfaces, its protocol stack is divided into two layers. All the UMTS-related issues are in the radio network layer, while the transport network layer contains standard technology used for the underlying transport. The Iupc interface only handles signalling messages so there is only one plane, the control plane.

So the only important protocol here is the PCAP, which defines the signalling messages exchanged over the Iupc interface.


PCAPPositioning calculation application part
RNCRadio network controller
SASStandalone SMLC
SMLCServing mobile location centre
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